


Negligence

by athirstygoil



Category: Undertale (Video Game)
Genre: Abusive Relationships, Alters, Beating, Broken Bones, Character Death, Dissociative Identity Disorder, Gen, Major Character Injury, Papyrus is an asshole, Past Abuse, Past Child Abuse, Past Neglect, Past Violence, Scars, Smoking, Soul injuries, alter ego, bad brother au, mentioned cigarette burns, or at least it's close to one, spit, spitting
Language: English
Status: Completed
Published: 2018-05-10
Updated: 2018-05-10
Packaged: 2019-05-02 09:07:32
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 1
Words: 6,427
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14541387
Author URL: https://archiveofourown.org/users/athirstygoil/pseuds/athirstygoil
Summary: Papyrus is an irredeemable shithead, and he still is when he discovers Sans has been missing for weeks.If you like Swap!Pap, prepare to hate him.





	Negligence

**Author's Note:**

> EDIT: I've recently recorded myself reading this fic by the way! If you want a listen, click over [here.](https://soundcloud.com/interimnity/read-with-goil-negligence)
> 
> This is my take on a Bad Brother AU in the Swap!Universe, where Papyrus is the older asshole brother who constantly belittles and beats his younger brother Sans. As you will see, the result is not pretty. 
> 
>  
> 
> Disclaimer: I'm not an expert on Dissociate Identity Disorder (DID), but I did my research! I hope I did it justice (bah dum tsss). (If not please inform me!)

He’d been smoking more frequently than normal. Feverishly, he willed his shaking phalanges into fists as he shoved them into his hoodie pocket. Orange sparks smouldered from the half-finished cigarette as Papyrus stomped through Snowdin. _Damn. FUCK._ Expelling a frustrated growl, a long leg swung with a jerk and knocked over a nearby trash bin. Of all the times to run the fuck out of cigs. And it was all because of Sans. 

 

It took him over a week and a half of coming home to an empty house to notice his brother’s disappearance. It took him another to half-heartedly scour (upon Alphys’ ~~threats~~ _insistence_ ) all the places Sans could have ended up. But everywhere Papyrus had looked or thought to search, (which in all honesty, was very few) no too-bright blue eyelights. No whines for Papy or ineffective pestering that he quit smoking. You’d think he’d be relieved--Sans after all, was very annoying. But no, every failure just agitated him more. Shit. Sans was taking up too much of his time. 

And _God damn_ that Alphys. Fucking talking his acoustic meatus off about his progress or if there were any leads to Sans's whereabouts-- He didn’t find jack _shit._ Not even that stupid scarf of his Sans liked to call his “cape.” 

Then again, with that trail of shitty stars gone, there was nothing to make him vomit.

 

Papyrus groaned as he wrung his hands into the fabric of his pocket. He’d be ~~yelling at~~ _calmly reassuring_ Alphys had he not chucked his phone into the goddamn river. It was, after all, an act of frustration driven by the Captain’s relentless calls. He had the gumption to fish it out with a bit of blue magic, but it still was in the water long enough to drown it. 

Stupid Sans. In hindsight, how _else_ would Papyrus add to the multitudes of messages about how ungrateful Sans was, and how weak and useless of a monster he had to be to get himself kidnapped or some shit. He’d even sent text after passive aggressive text asking if his brother had finally gone and dusted himself. 

 

Technically, all losing his phone did was inconvenience him. By like, a lot but Papyrus was certain Undyne would reimburse him should he… _beg_ it from her enough. 

Besides, if anything, it gave him a better excuse to show up late to Sentry duty. After all, what could Alphys even do? _Fire him? When he was just being a good brother and searching for his lost sibling?_ What a **joke**. Hilarious. Even Papyrus couldn’t have planned it better himself. 

...Still… 

His teeth clamped hard against the filter of his last cigarette. Papyrus didn’t think he’d end up so frustrated about all this. Then again, he never gave too much thought about his baby bro until he realized he couldn’t. find. him.

 

Upon hearing this, Alphys (probably in a half-hearted attempt to make him feel better and quell her own worry) insisted that Sans is a very capable skeleton despite his appearance, and that he more often than not, had proven himself to her countless times. Papyrus found this to be complete and utter nonsense. Though he humored her, inwardly he very much begged to differ. _Sans_ strong? _Sans_ capable? All he did was mope about in Waterfall and talk to that huge octopus creature if not the silent ferry person. 

And if it wasn’t them, he’d go about in that fake, childishly painted cardboard armor of his and trick others into thinking he was in the Royal Guard. Alphys in all her might and fury couldn’t convince him that Sans was worth the time and effort she spent on him. Because all Sans was was just a stuck-up, little monster-pleaser as far as Papyrus was concerned. Sans would literally throw himself at others for the slightest bit of attention and did nothing to show that he was a capable monster, let alone more than a giant brat.

How Alphys could lie to him like that was beyond him. How Papyrus let himself listen to that bullshit was beyond him.

 

 _Bastard doesn’t deserve all this time I’ve wasted looking for his sorry ass,_ Papyrus seethed as he finally slumped into his sentry station. _Fucking Alphys, forcing me to take time outta Muffet’s to go get his piece-of-shit butt home._ Taking one last drag from the dying filter, Papyrus exhaled heatedly. _What a bitch. Ungrateful asswipe is better off as dust at this rate._ Fingers reached into his pocket for his missing phone and instead, retrieved his lighter. He flipped it open and he gazed heatedly, yet thoughtfully at the flame.

 _I swear if I get my hands on that fucking turd, he won’t even last a minute back. I’ll make him regret wasting my fucking time. Even if it means I dust him myself. That’ll teach him._

 

Papyrus in his monologue barely noticed the air fizzle with the crackle of magic as the beginnings of a rift opened a few feet away from him. _I’ll make him **beg**. Make him bleed whatever marrow he’s got left in those twiggy bones of his. And I’ll--_ He flicked the lighter closed when he finally saw the tear in space. Sockets wide, Papyrus’s teeth snapped the filter in half. _Fuck I’ll have to find more--_ And just as the split grew, he dove behind his station. 

Peering warily at the ground, Papyrus furrowed his brow ridge. _What the hell--_ There was no one that he knew of in the Underground that could teleport. At least, not as flashy and showy like this. Was this some space-time traveler visiting? Were they a threat? He had heard of the Multiverse Theory but didn’t think it to any more than just that. Edging closer just enough to make out the rift, Papyrus waited.

 

The crunch of a boot against the ice almost echoed in the stillness. And as they stepped authoritatively out, the portal yielded to encompass their form. Papyrus counted three long seconds before he chanced a quick peek. 

The lone monster had their back turned towards him.

What an idiot.

They didn’t look like too much of a threat if they were the only invader. Papyrus knew he could take them. Heck, even _he_ was decent at mano y mano. Least his target play dirty, but Papyrus wouldn’t count that against them. He’d definitely do it too. Casually rising from his hiding place, the tall skeleton cocked his head as he looked them over.

 

Aged metal pauldrons curved upward into sharp points atop a rounded steel breastplate. Fiery blue and purple swathes of magic flashed momentarily as the monster ground their spiked combat boots into the snow. Their ragged and stained head-covering rippled with the wind the portal brought with them as their head lifted proudly.

What did this beansprout of an invader think they were? Papyrus fought to stifle a laugh. Clearly to miss Snowdin entirely was a dumb mistake. _Because they had to go through him._

Striding closer, Papyrus’s grin grew. This skinny bitch of a Numbskull. With their _majestic fucking cape_ flapping in the goddamn breeze--

This was gonna be a piece of Grillby’s specialty cake with a cherry on top. 

 

Papyrus drew his hand out, magic sparking the air when he noticed the vague shape of a star hidden in all that grime of a once-blue scarf. _Wait…_

Squinting, Papyrus waited as the intruder turned to walk toward Snowdin. _And the wind brushed the makeshift hood enough to reveal a cranium._

_It couldn’t be…_

 

The gears clicked in his skull as his grin lowered to a frown.

And his voice carried over a mix of disgust and anger.

“ _Sans?_ ” Blue and purple eyelights snapped toward the direction of his voice and shrank before brow bones lowered in a testy furrow. And it was here Papyrus got a look at the left side of his scum of a brother’s face. Three long, glaring claw marks left deep gashes across his eye socket. And as a result, his now purple-stained eyelight shaped into a vague triangle instead of the usual, godforsaken excuse of a star as Sans stared at the lanky monster before him. You could say it was a step up really. Better than that dumb excuse of a Halloween costume. But in no way was Papyrus gonna admit how “cool” his baby of a brother suddenly looked.

 

“Why you _LITTLE SHIT_ ,” Papyrus roared. “I HAVE HALF A MIND TO _BEAT THE LIVING SHIT OUTTA YA **YOU SON OF A BITCH!**_ ” With the flick of his wrist, he summoned a glowing femur. And as Papyrus strode to close their distance, an unexpected smile quirked about the side of Sans’s mouth as he shook his head, amused.

“Wouldn’t that make _you_ one, bilgerat?” he chuckled aloud. Stopping short, femur in hand, Papyrus’s brow ridge rose. When did _Sans_ of all people fire off comebacks? Papyrus was almost impressed, astounded even. _When did Sans even think it possible to insult **him?**_

 

Enraged, Papyrus felt a nerve snap.

“So where ya been _Bro?_ ” he asked brazenly. “ _Playing dress-up?_ HA. Where’d ya get _that_ get-up? I didn’t think the Underground had any cheap Halloween shit left!” Casually lifting his arm to crack down on his sibling, Papyrus was surprised to find the blow hit empty air. Sockets in an annoyed squint, he turned to look behind his back.

There was Sans, a few feet behind him, with a fucking _smirk_ pulling at the unmarred side of his face.

 

“Did you really think I’d let you hit us?” he asked, voice uncommonly prideful. “After all those times he let you get away with it?” The slight spark of humor was replaced by a dead, unflinching stare as his eyelights disappeared. “ _N e v e r a g a i n._ ”

Papyrus’ brow furrowed slightly at the pronoun choice, but it was overshadowed by the sheer arrogance of the skeleton in front of him. Okay. That was it. If there was any hope this little fucker was ever gonna beg for forgiveness, they were way past that. Evidently, Papyrus wasn’t sure why he bothered. He was _still_ gonna beat his boney ass.

Spitting a wad of tar from his conjured throat, Papyrus cackled slowly.

 

“Well aren’t you a sick little fuck,” he smirked bemusedly. “Playing your poor brother like a fiddle. Making me believe you were fucking gone for good. When you _clearly_ were coming back.” His smirk grew as his stained teeth twitched partially into a mocking snarl. “It’s like you came back _just for me. So I could beat you senseless. How thoughtful of you. Filthy bitch._ ” Seemingly uninterested, Sans brushed away at his comment like it were a pestering fly.

“Oh please, spare me the niceties. I didn’t come back for your petty insults,” he snapped.

What the absolute hell. Sans _never_ spoke like that, even to berate him. It was always ‘Papy _do this_ ,’ or ‘ _Please don’t hit m--_ ’ before he’d conk him in the skull or something. Damn, if anything Papyrus did miss the crack of his knuckles or palm against those brittle ass bones. Ha. Good times. 

 

“Then why the hell bother?” he pried slowly, “if it’s not to satisfy me? _Pacify me?_ ” The heated breath Papyrus expelled came out with a chuckle. “Indecisive piece of shit.”

And then out of the blue, Sans replied with a loud, raucous laugh. 

“SEE--” he howled, “I SWEAR YOU’RE SUCH A MONGREL--” his laughter cut him off momentarily as he fought to breath. “LIKE YOUR INSULTS ARE A MERE FACADE OF YOUR FETISH FOR TORTURE. And you--and you’d do it to him--” he gasped, laughter subsiding, “because who the fuck would ever love a godforsaken asshole like you?”

Shocked, Papyrus stared, teeth agape. That…that actually _hurt._ What the hell. _When in the hell._ Shock became anger. Anger became rage.

ALRIGHT THAT WAS IT.

 

“YOU’RE ONE TO TALK YA WEAK PUNK!” he shouted. “WHO IN THEIR RIGHT MIND FINDS A DISFIGURED MUG LIKE YOURS ATTRACTIVE?” The laugh that rang from that infuriating shit-stain pissed him off _so. much._

“Oh, haven’t you _heard?_ ” Sans countered with a haughty smile. “ _All the ladies like a good scar._ Shows that I survived something _big. Fierce. And_ I think it a step up, don’t you think? I always revelled in attention after all.”

_**MOTHER FUCKER WAS HE SPINNING THIS ON HIM WHAT THE FUCK** _

 

“Then you’re a liar _**and** a self-centered fuck!_ ” Papyrus shot back, wielding the femur in an offensive stance. With renewed vigor, Papyrus about closed their distance by a few feet, his glowing construct prepared to bash into that exposed part of Sans’s ribs when the triangular eyelight glowered. Tyrian magic streamed down his left arm, and materialized into a sharpened humerus the length of a sabre at the snap of Sans’s elbow. 

 

Teeth set in a threatening, yet gleeful scowl, magic smoked from his socket as Sans stomped forward and swung to pierce. Eyelight shrinking, Papyrus blocked it. And as magic sparked between the two, a chuckle escaped between his yellowed teeth. And it only grew when Papyrus forcefully thrust his weapon forward, until he hacked out another mess of tar from his conjured tongue and throat.

“ _When the hell were you gonna tell me you know how to fight?_ ” Papyrus sneered, expelling a lump of tar at his brother’s scarred face, “You useless bag of bones.” Sans blinked as the blackened saliva made contact. If he recoiled, he didn’t make any exaggerations. Blue magic encompassed the spit and tossed it into the snow where it belonged as Sans merely grinned widely, almost manically.

 

“ _Wouldn’t **you** like to know, asshole?_ ” he hissed. 

At this, Papyrus scowled. Who the hell did this fuckwad think he was? Sans swung again as if nothing happened, and continued to smile broadly as Papyrus clumsily dodged more pointed lunges. _Why in the fuck did this remind him of fencing? **When the hell did Sans know how to fucking fence?**_ Eyelight blazing a fiery yellow-orange, the tall skeleton emitted a rallying cry as he doubled his efforts. And if he could wipe that smug-ass grin from his face, oh Stars would he enjoy that.

“ _So Alphys **wasn’t** lying when she said you could fight. I thought that dumb bitch was just spouting bullshit!_ ” And he caught the scrunch in his brother’s face as it clicked in his dumb skull that Papyrus insulted his ~~best friend~~ biggest sympathizer. Attacking this time with a swell of confidence, Papyrus’s arm swept forward as a wave of bones met Sans. Blocking with his own wave, Sans pierced the projectiles almost with ease. _While **laughing** the entire time._

 

And it pissed Papyrus off. _If he were water he’d be fucking boiling over._

“Nothing to say?” he laughed haughtily instead. Tossing his summoned femur and catching it, Papyrus cocked his head as his little brother stood his ground for another attack. “Maybe that bitch shouldn’t even be Captain with how crooked her priorities are! You were such an annoying little twat. She might as well have tossed you aside herself!” Tossing his weapon in the air again, he nearly dropped it when Sans spoke.

“You know, you’re a very talkative Rat,” he replied condescendingly clear. Hard eyelights glared at Papyrus as a callous grin widely encompassed his face. “ _Perhaps I ought to exterminate you here and now._ ”

 

Reflexively laughing aloud, Papyrus covered a socket with his free hand.

“Is that what I am?” he chuckled cynically. “Maybe I outta _jog your fucking memory._ ” Launching himself at Sans, he lifted a leg out to kick. “ _I’m your brother you moron!_ ” Papyrus yelled as the heel of his flip-flop made contact with bone. A snap and Papyrus found Sans careening into the forest. “Heh,” he grinned widely before a short, raspy laugh escaped from his teeth. “Bitch didn’t see it coming.” Feeling his cargo pockets for a cigarette pack, Papyrus groaned when he remembered he was all out. Huffing, he turned toward his station again, only to suddenly feel a sharp pressure against his spine. 

“You seem awfully interested in me for someone who claims to be my brother.” _What the--_ Turning with a jerk, Papyrus snapped angrily as he summoned another femur.

 

“ _IT’S ME YOU LITTLE SHIT._ ” Sans leaped backward, parrying with his weapon as their bone constructs clashed. The sudden show of more-pointed-than-normal canines had Papyrus furrowing his brow. _Were his teeth always so sharp?_

“I’ll know for certain when I get your dust on my hands,” Sans smirked forebodingly. And it was when Papyrus found himself getting pushed _backward_ did he realize all at once that Sans was at par, if not _stronger_ than him.

Struggling to maintain the upper hand, thoughts raced through Papyrus’s skull. When the fuck did Sans get so fucking strong? _This pathetic excuse of a weak **baby**?_ A match for _him?_ Pissed off as hell, Papyrus ground his stance and summoned a bone from the ground with the slightest of gestures with his phalanges. As it punched up from the snow, the shorter skeleton launched himself back, eyelights large with surprise.

And it was here, that Papyrus grabbed hold of his Soul. Pulsating erratically, Sans grimaced as Papyrus yanked the cumulation of his being closer. Examining it, his sockets widened as if intrigued.

 

Well what did they have here?

Amidst the lighter blue was a patch of purple. 

Explained how in the hell Sans grew a pair of fucking balls.

_It wasn’t even him._

His little brother really _was_ a freak. Whoever the hell this was, there was no way this could be Sans. 

Empowered by this suspicion, Papyrus smiled cruelly as he slowly constricted his magic around the cumulation of this imposter’s being.

 

“Tell me something _Sans_ , or if you’re just some parasite masquerading as my pathetic excuse of a brother--” he spat, “what have you to gain by visiting little ol’ me hm? Is it revenge? Did my fuckwad baby brother _cajole_ you into helping him? _Did he put stars in his sockets so you’d pity him?_ ” When “Sans’s” brow ridges twitched at the comment, Papyrus felt a surge of confidence. _He was right. “ **HA**_ ,” he continued sharply. “ _He’s always been a manipulative bitch!_ ” 

Swinging with all his might, Papyrus managed a blow to the smaller skeleton’s face. Reeling, “Sans” fell to the snow, arm out to brace himself. Papyrus’s open hand clenched shut as he threw his supposed sibling into the ground. Stepping over him, the tall skeleton brought his weapon down over “Sans’” cervical vertebrae, as gloved hands grasped at the heavier bone. 

“Then what does that make _you, Nega-Sans?_ ” Papyrus jeered, pushing his weight into crushing this fucker’s neck, “ **Is he such a conniving shit that he gets others to fight his own battles for him?** ” Papyrus’s glowering eyelight met this imposter’s mismatched ones and without warning, he felt himself getting forced back. 

 

“ _Get Off Me You Filthy Rat,_ ” the scarred skeleton growled dangerously, fighting for leverage.

The fury in those blue and purple eyelights caught hold of Papyrus, and he felt a swell of anger at the retaliation. 

“You don’t get _to tell me **what to do!**_ ” he enunciated, driving “Sans” forcefully into the snow by his Soul. “All this is just some game to you, isn’t it? HA HA! Pretending to be a goddamn hero, WHEN YOU’RE NOT EVEN FIT TO BE A GUARD!”

 

Shifting defiantly, “Sans” glared up at him from the snow, grip still tight against Papyrus’s chokehold. The blue and purple of those eyelights flared as a menacing heat hung in the air around him. 

“AND YOU THINK _YOURSELF_ WORTHY?!” “Sans” screamed, “Whoever allows idiots like _you_ in the guard needs to rethink their hiring process!” Releasing his hold on the orange bone, he thrust his knee into Papyrus’ spine. His other foot planted into Papyrus’ hip and to his surprise, “Sans” slid away. Rolling into a crouch, “Sans” transitioned smoothly into a running start despite the weight on his Soul as he glided past Papyrus. Hooking the ball joint of his newly summoned humerus onto Papyrus’s ankle, “Sans” knocked him off balance. 

 

Papyrus fell with a flummoxed cry and the moment his boney ass hit the snow, a painful sting drove into the cartilage of his patella. With a scream, he grasped at his knee as Sans knocked the femur from his grasp. Magic no longer holding him down, he dislodged the sabre-like point and aimed at Papyrus’s neck. It dripped with what little magic bound his bones together there as blue and purple eyelights nearly sibilated with malicious intent. In his now compromised position, Papyrus began to rethink his strategy. Fighting back was one thing, but outright injury?! If he was suspicious before, he was certain now. Whoever this was shared his pathetic brother’s face, but it definitely wasn’t Sans.

There was no telling his intentions, but if Papyrus pushed the wrong button, this Sans could very well kill him. No matter how fucking annoying this fucker was getting, Papyrus had enough street-smarts to lean toward self-preservation.

“Consider that as punishment for your arrogance,” “Sans” glowered as he stepped forward threateningly. His free hand reached out, and clenched into a fist as Papyrus’s soul dinged blue.

 

“Wait--waitwaitwaitwait!” Awkwardly scrambling backward, the tall skeleton begged with frightened sockets, metacarpals facing “Sans” in surrender.

“Look, I don’t wanna hurt you Bro,” he whimpered, hoping to appease him. “I was just--”

“Sans” answered his pleas with a kick to the face, and Papyrus stumbled back, undecided on whether it were more important to protect his knee or his already-bruising cheekbone. This imposter was clearly not taking any bullshit. 

 

Analyzing him from a proudly raised chin, “Sans” scoffed, as he swiftly kicked Papyrus in the ribs. Gasping, the tall skeleton curled into the fetal position, and whimpered for dramatic effect. 

“I don’t see why you fear him,” “Sans” tutted, almost as if he was talking to another person. “He’s clearly nothing but a coward with a big mouth.” Grinding his boot into Papyrus’ sternum, “Sans” glanced down at him, triangular eyelight smoking only just so. “But seeing as how his incessant chattering is what hurt you in the first place well,” his teeth rose in a cruel smirk, attention directed at the skeleton beneath him. “I’d be happy to be rid of it for you.” 

Shrugging, he tilted his skull ominously. 

 

“Or, you know,” he sang. “I could rip him apart first. Limb by limb perhaps. Or break his phalanges. Whatever you think is more appropriate.” Scoffing suddenly, “Sans” furrowed a brow ridge before grinning wide enough to show his gleaming canines.

“Oh I like that too~”

One step forward and “Sans” stiffened with a jerk. Teeth tensing into a clenched scowl, his eyelights flickered a moment before “Sans” growled. Peeking carefully up at him, Papyrus saw the purple smoke recede slightly.

“Are you sure?” “Sans” asked suspiciously. “You know this scumbag doesn’t deserve it.” A beat and Papyrus saw him physically slump forward. “If you _insist_ ,” he heaved exasperatedly. “But don’t say I didn’t warn you.”

 

The arm threatening him with the bone shook slightly as “Sans’s” sockets emptied. And as his eyelights returned, Papyrus caught the barest hint of a toothy, but not unkind smile as starry blue eyelights rose to meet his. To Papyrus, his demeanor changed drastically. No longer did he stand prideful. He seemed more tired, with a slight slouch. More reserved, as the gloved hands drew the curved end of the humerus nearer to his chest.

“You know,” Sans (it had to be, right?) laughed pitifully. “I thought I could do it. I thought I could follow through.” Clutching the sharpened bone so tight, his distal phalanges scraped into the palms of his gloved metacarpals. The humerus had paled to match his now blue eyelights. 

“I spent a long time actually, thinking about how I’d be when we met again. I thought about...how much stronger I’d be. How less of a pushover--and how confident in myself I’d be.” Grinning as if playing on a sad joke, Sans chuckled. “Clearly I’m not suited for the task I gave myself. Just talking to you has already ruined it.” He paused a moment. 

“I’ve thought about other things too. Like if I let Tyrian dust you, I wouldn’t feel the weight of the guilt. It wouldn’t be my actions so therefore I’d be justified.” Eyelights steadily gazing at Papyrus, Sans frowned. “But you’re right,” he concluded, voice breaking slightly. “I need to stop letting him fight my own battles.”

Papyrus knitted his brow ridges impatiently. If he was gonna spew out some overused spiel about being the better skeleton he was gonna-- 

 

“So instead of relying on him to do it,” Sans breathed with conviction, “I’ll rely on myself.” Papyrus froze, sockets smoking as a smirk pulled at his teeth. 

“You don’t have the balls,” he challenged. “Whoever the fuck that tyrant was fucking did. But _you?_ ” Papyrus laughed aloud wickedly, mockingly. “ _You’re just a weak-ass little bitch._ ” 

 

A single tear trickled down his zygomatic process as Sans clutched at the shaft of the humerus. Swallowing, Sans stared down at his brother. ~~The one he so badly wanted to love him back but never did. The one he loved so wholly but knew was only one-sided.~~

“I love you, Papyrus,” Sans said simply, tears wetting his sockets. “Always have. Always will.” And with a smile, he raised the sharpened bone over his head as a blade of purple magic formed atop it.

“Goodbye.”

And with all his might, Sans swung.

\----

When his swing was met with resistance, Sans looked back at his tormentor, his abuser since he was a child--

And his eyelights shrank.

Marrow trickled from his metacarpals as Papyrus struggled to lift the cutting edge away from him.

 

“Honestly, didja think I was gonna take it lying down?” he snapped, a crooked grin creasing his face. “Look at you--you’re literally shaking! Letting your tyrant friend go was your biggest mistake, Bitch.” Despite his blue Soul, Papyrus rose, and his grip on the blade tightened. 

Sans’s soul sank. And the moment his hold on the bone slipped, Papyrus used it to throw him into the snow. “You’re a bigger fool than I thought,” the tall skeleton jeered. Scrambling, Sans crawled away backward, gasping as his Soul tightened with distress. Blue magic now dispelled, Papyrus walked freely. Dislodging the blade from his metacarpals, he tossed it aside and it dematerialized into sparks of blue. 

“Y’know,” he cooly smirked, “I think I’m gonna enjoy fucking you up.” He grinned widely. Fiendishly. “Just like old times, am I right?”

“No--” Sans cried out, frozen in fear, “NO!” And it was like he was back in their living room, protecting his skull from the worst of the hits as Papyrus beat him near-bloody--

The snow felt like cold tile under him, and his breaths came out in shrill gasps as Sans shrank into himself.

 

 _“Remember where you are--”_ a calm, commanding voice penetrated the panic. Tyrian. _“Remember **who** you are. **He can’t control you anymore. I won’t let him.** ”_

And as Papyrus lifted his arm to club him in the skull, Sans rolled out of the way last minute. Getting up, Sans ran from his brother. 

_“Forget what I said before,”_ Tyrian continued, _“you can fight him just as well as I. You’re strong, Sans. Stronger for doing this--stronger for trying.”_ And a rush of warmth engulfed his being as Sans summoned a bone for defense. 

_“You can do it,”_ his alter encouraged. _“I will help you.”_

Emboldened by this, Sans stopped running to face his oppressor.

“We’ll do it together,” he said after taking a deep breath. And his left eyelight morphed into a triangle as purple magic took over the blue.

 

“That’s what I like to hear,” Tyrian smirked. Grounding his stance, he summoned a wave of bones at Papyrus, who was a stone’s throw away. Dodging the attack, the taller skeleton swung his arm out, releasing a wave of his own. The bone in Tyrian’s hands lengthened and he blocked the orange bones with the now-purple poleaxe. With a sweep, Tyrian threw snow at Papyrus before launching himself forward. Blindly, Papyrus wiped snow from his sockets in time to see the more furious Sans swing--

Knocking the tall skeleton over, Tyrian managed a deep slice to his cigarette-burned hoodie.

“Taking advantage of the weakness of others now?” Tyrian taunted. “ _No wonder he calls you an asshole._ ”

“LET THAT FREAK SAY IT TO MY FUCKING FACE!” Papyrus bellowed, carelessly bashing a summoned bone into the blade of the poleaxe. Laughing mockingly at him, Tyrian spun the shaft of his weapon, slashing into his hoodie sleeves as Papyrus attempted to block. Purple eyelight now seamlessly blue, Sans struck him in the ribs with the rod of the poleaxe as the blade dispelled.

 

“ _You’re a fucking asshole, Papyrus!_ ” he shouted, as the tall skeleton hit the snow. Starry blue eyelights smoking furiously, Sans vaulted toward him and kicked at his brother’s spine with the heel of his boot. The heavy combat boot met the vertebrae with a crack and Papyrus screamed bloody murder.

“ _ **MOTHER FUCKER!!**_ ” Haphazardly dragging his lower half through the snow, Papyrus barely traveled a few feet when Sans caught up to him. “What happened to the little fucker who’d never hurt a fly?” Papyrus spat through a tensed jaw. Whirling spitefully to face him, he yelled, “If you do this, _you’re no better than me!_ ”

A heavy boot stomped into his rib cage and Papyrus gasped at the impact.

“ _F-fuck--_ ” he weakly breathed as his Soul was then encased in blue.

“I never said I was better than you, Papyrus,” Sans replied matter-of-factly. “In fact, I worked very hard to get where I am.” Pausing a moment to reflect, Sans blinked. And a hollow chuckle rang through his ribcage. “It’s funny,” he professed. “I think we’re both the bad guys in the end.” Leaning towards his brother, Sans locked suddenly hardened eyelights with his.“I’ll just have the peace of mind knowing,” his teeth pulled widely, gleefully into a smile. “That once I dust you myself, _you’re not fucking coming back._ ”

The look of shock and helplessness on Papyrus’s face made Sans swell with a sense of power he never knew he could experience.

And God did he enjoy it. 

 

 _“Don’t get cocky now,”_ Tyrian warned. _“Finish what we started.”_

Brandishing the staff, Sans drew a hand over tip of the shaft as sparks of blue elongated it into a spear.

“A sick fuck like you doesn’t even deserve a quick death.” 

The spear plunged downward, lodging between Papyrus’s ribs--nicking the bone with the sheer force of the thrust. 

Magic-weighted hands clenched like claws and grasped forward, at the shaft impaling him--

Papyrus barely had time to glare hatefully as Sans removed it jaggedly and speared through another set of ribs. This time, Papyrus jerked about, spastically wriggling--blue magic restraining him enough that he only managed to flop pathetically like a fish out of water. Sans thrusted violently downward and the spear exited through Papyrus’ back, making the tall skeleton crushingly intimate with the ground.

 

Eyelights wide in an almost blank stare, Sans knelt down in the snow and brushed the torn fabric of his hoodie aside. 

Noticing this, Papyrus feebly lifted his head as Sans reached into his ribcage.

“What are you--”

And roughly, Sans extracted his glowing soul from its boney prison. Papyrus, if he had the energy and _hate_ to bring up his eyelights, knew they would be shrinking rapidly.

“No--” he gasped, panicked. “ _Don’t!_ ”

Displaced Soul pulsating in distress, Sans scrutinized it.

“I knew you hated me,” he muttered. “Why else would you hurt me so much? Feeling your soul now though,” gloved hand cupped around the pathetically blue-tinted soul. “It only confirms my suspicions.”

Summoning a dagger, he gently nudged the blade against the cumulation of his brother’s being. “I wonder if you’ll ever know what it’s like to be whole.” Smiling lightly, Sans ran the edge just over the delicate membrane of his soul.

 

It would be so easy to just stab him at his most vulnerable, to watch Papyrus writhe on the ground like a cockroach as Sans oh so delicately hacked his soul to pieces. To watch as his limbs disintegrated before his very eyelights. To force him to feel every little bruise and wound he ever inflicted on Sans’ body.

It would be so easy.

But Sans wasn’t that cruel.

And neither was Tyrian.

But Stars did he want to inflict the longest, most excruciating pain he could ever deal to Papyrus.

Sans loved him, yes.

But God did he also hate the fuck out of him.

 

“Funny, since you call _me_ the freak,” he finally muttered.

“Look,” Papyrus reasoned between gasps and grinding teeth, “if you’re gonna do it at least let the tyrant do it. He’s got better aim.” Sans pretended to think about it while he fingered the Soul through his gloved phalanges.

“Why else do you think he hasn’t taken over?”

Sans watched bemusedly as Papyrus’ sockets became wide saucers at the realization. And with the lift of the dagger, Sans felt the Soul in his hand quiver as the sharp end sliced a centimeter in--

“You can’t--” Papyrus spluttered, physically cringing at the tiny cut to his core. “Alphys--Undyne--they’ll come looking for me--” Squeezing his Soul made ~~the rotten bastard~~ Papyrus reflexively wince, and a shot of fluid dribbled from the exposed organ.

“If there’s nothing to find it wouldn’t be worth now, would it?” Sans uttered unwaveringly.

The fact that Sans could _feel_ his fear radiate just made it all the more better.

“They’ll--” he tried again unsuccessfully, “ _I’ll--I’ll change!_ ” Papyrus cried out. “ _No more beating, no more cigarette burns--_ ”

“As if you can redeem yourself--” Sans laughed resentfully.

“ _We can be a...a **family** again!_ ” Papyrus proposed, voice shrill. At the silence, Papyrus grinned sheepishly. “L-like we should have been.”

Sans glanced down at him and flicked his pitiful, specious statement away, almost bored.

“Empty promises,” he concluded. “It wouldn’t be beneath you to make them anyhow,” he smiled bitterly. “We were never a family to begin with.”

 

All useless negotiating aside, Papyrus gazed up at him, now angered.

“Not like I had a fucking chance when you fucking _left me._ ” Without thinking, the glower in Sans’s eyelights smouldered bright. To the point the malicious intent clouded the fear that radiated from the thinly veiled confidence of the frightened Soul in his grip. 

“ _I_ left you?” Sans repeated, suddenly quiet. “ _I_ LEFT _YOU?!_ ” His loud voice carried over, and rang in the stillness around them. Despite wanting to keep himself emotionally distant from his stupid ass of a brother, despite Tyrian’s warnings that he keep himself in check--, Sans felt tears prickle at the corners of his sockets. “ _ **YOU LEFT  ME!**_” 

Another bone dagger materialized and cut through the Soul in his palm. It barely missed the center, and the blade retreated as soon as the damage was done. Stiffening, Papyrus gasped as he immediately felt a part of him dust.

“You left me _the moment you decided I was nothing but trash to you!_ ” Sans yelled. “ _When you decided to blame every fucking thing wrong in **your** life on ME!_ ” The tears flowed freely now, and trickled down his mandible.

“ _I’M NOT A MISTAKE!_ ” Sans screamed. “ _I’M NOT YOUR FUCKING PUNCHING BAG, AND I’M **NOT** HERE TO SOAK UP YOUR PERSONAL GRUDGE!_ ” Taking a breath, Sans clutched the dimly pulsing Soul firmly, exacerbating the wound further in the process. Another part of Papyrus began to dissolve.

“I’m here to live,” Sans declared. “Not under your fucking influence,” he spat, “ _Or your terms._ ” Wiping at his tears with the back of his hand, Sans sobbed a moment. “I will live under _mine and mine alone._ ”

 

“That’s why I have to kill you,” he divulged, head shaking as he gazed at the ground beneath them. A loose powder joined the snow. “If I dust you by my own hands--I’ll know.”

Taking a deep breath, his hold on Papyrus’ weakly beating soul loosened slightly.

“I’ll know,” he whispered. “That there’s nothing left to hold me back.”

 

“so do it then,” Papyrus muttered, sockets frozen in a blank expression. “you’ve already gone this far.” Sans’s head rose. The Soul in his hand was already half dusted. Papyrus was just a torso and a skull now. The limbless doll of an uncaring owner.

“As much as I hate you,” Sans choked out, “I still love you too, Brother.”

Papyrus smirked feebly in understanding.

“some fucking plan that turned out to be hm?” Closing his sockets, Papyrus took one last breath. “then i hope you find your happiness bro,” he whispered. “wherever it may be.”

 

Covering his teeth with his now powder-covered gloves, Sans watched as his tormentor, his bone and marrow, dissolve.

 

 

_“I never thought you had it in you.”_

Breathing hard, Sans stared as the dust gently piled in front of him. Eyelights the size of pinpricks, he hesitantly reached for where his brother once sat. The hand that still held the bladed bone shook. 

_“I was merely going to cut the part of his soul that manifested his tongue, but I do like this outcome just as well. A little messy, but it wasn’t like he deserved a quick death.”_

Sans’s face scrunched with a sob.

_“Are you alright?”_

Sans dropped the weapon and it dematerialized in the snow. Falling to his knees, his gaze blurred as the tears rolled down his face. And he felt a comforting warmth in his chest as the voice in his head hushed him soothingly.

_“It’s hard, losing someone you loved. I know. But you did it. You’ve won. You’re not tied to him any longer.”_

Wiping the tears away with the heel of his palm, Sans hugged himself before looking back to where they had shortcutted in. The swathes of blue and purple sang in the air as the portal opened once again. And a warm feeling engulfed his Soul as his alter encouraged him forward.

 _“We can only go forward now,”_ Tyrian whispered. Turning Sans’s attention to the Universe that awaited them, he reminded him gently, _“Our real family is waiting.”_

Teeth in a growing smile, Sans walked them onwards. 

“Let’s go home.”

 

Turning back, he beamed warmly at the snow.

“That goes for you too, Brother.”


End file.
